Bug#669314: linux-source-3.2: After mounting nfs export, kernel forces trailing slash for export in /proc/self/mounts

[Chris Hiestand <chiestand@salk.edu>]

Package: linux-source-3.2
Version: 3.2.15-1
Severity: normal
Tags: upstream

Dear Maintainer,

I believe it is convention to leave a trailing slash off of the nfs export
in /etc/fstab, e.g.:
nfsserver:/srv/ubuntu-32 /mnt/ubuntu-32  nfs ro,nfsvers=3,soft,intr,tcp,nodev,noatime,nosuid,rsize=32768,wsize=32768

I expect /proc/self/mounts to show (notice no trailing slash on the export):
nfsserver:/srv/ubuntu-32 /mnt/ubuntu-32 nfs ro,nosuid,nodev,noatime,vers=3,rsize=32768,wsize=32768,namlen=255,soft,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=198.202.1.1,mountvers=3,mountport=41576,mountproto=tcp,local_lock=none,addr=198.202.1.1 0 0

But instead in /proc/self/mounts I get (notice the trailing slash):
nfsserver:/srv/ubuntu-32/ /mnt/ubuntu-32 nfs ro,nosuid,nodev,noatime,vers=3,rsize=32768,wsize=32768,namlen=255,soft,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=198.202.1.1,mountvers=3,mountport=41576,mountproto=tcp,local_lock=none,addr=198.202.1.1 0 0

This simple change has a lot of implications because lots of things parse /proc/self/mounts, for example mount.nfs and umount.nfs

user@hostname:/proc/self$ sudo umount.nfs nfsserver:/srv/ubuntu-32
umount.nfs: nfsserver:/srv/ubuntu-32: not found

And if you run "sudo mount -va", mount will not recognize that the fstab mounts have already been mounted;
mounting all mounts twice on the same mount point. This quickly gets messy.

If there is a new convention to force the trailing slash in linux-3, we need to update our tools to handle
this change. If there is not a new convention, this is a bug.

As a workaround, I can boot into the squeeze kernel, linux-image-2.6.32-5-amd64, and the problem
no longer reproduces. This is why I believe it is a problem in the kernel and not in nfs-common.

Thanks,
Chris

-- System Information:
Debian Release: wheezy/sid
  APT prefers testing
  APT policy: (900, 'testing'), (350, 'testing-proposed-updates')
Architecture: amd64 (x86_64)

Kernel: Linux 3.2.0-2-amd64 (SMP w/12 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages linux-source-3.2 depends on:
ii  binutils  2.22-6
ii  bzip2     1.0.6-1

Versions of packages linux-source-3.2 recommends:
ii  gcc                   4:4.6.2-4
ii  libc6-dev [libc-dev]  2.13-27
ii  make                  3.81-8.1

Versions of packages linux-source-3.2 suggests:
ii  libncurses5-dev [ncurses-dev]  5.9-4
ii  libqt4-dev                     4:4.7.4-2

-- no debconf information